The invention relates to control boards and more particularly to ones with a closed frontal panel constructed out of a mosaic of right rectangular parallelepiped components each having an enclosing front panel.
The use of mosaic boards is known from a Siemens publication titled "Mosaic Technology, One System--Two Sizes," order no. A19100-E142-B227 (114 544 WS 8842), published August, 1984. A mosaic board consisting of components whose individual square frontal panels can be removed according to this publication, comprises: primarily inert components without any surface symbols, among them also dummy components with purely visual and unchanging symbols to model and represent any desired distribution arrangements, and active components with variable display and/or actuating mechanisms. Given adequately small-sized display and/or actuating mechanisms, said active components can be inserted into the individual inert components upon removal of the frontal panel and positioned therein in a detachable fashion.
In plant control engineering according to "Siemens catalogue" W13, 1984, it is a known procedure that so-called standard fields are to be fastened with a front side aspect ration of 2:1 along evenly spaced parallel mounting rails (compact grid). These standard fields have locations for light compartments and/or pushbuttons, and a cover plate with indicator windows as well as cutouts for projecting actuating mechanisms. On the reverse side of the locations there are connector contacts for up to three plugs.
To install larger devices or instruments in such compact grids, snap-in plates can be inserted from the frontal side along with the device or instrument involved, or screw-on plates can be inserted from the rear side. The inert fields which are not fitted with display and/or actuating mechanisms or instruments, are designed in a flat pattern with an aspect ratio of 2:1 and also held exclusively by the compact grid of mounting rails.
It is the object of this invention to provide mosaic boards out of individual components without any mounting rails, which comprise disconnectable components for plant control engineering and in general mosaic boards which will require fewer overall components to build a specified board surface. It is a further object of this invention to provide an optional easily disconnectable mounting arrangement permitting the insertion of active components of various sizes as well as the insertion of devices of varying shapes in openings created by the omission or removal of at least one component.